Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic alcohol ingestion in the rat resulted in increased hepatic aromatase activity, elevation of plasma estradiol, and a decrease in plasma testosterone levels. Testicular incubation studies indicated that the source of the estrogen was not of gonadal origin but was, most likely, due to increased peripheral conversion. The failure of HCG in vitro to restore testicular secretion of testosterone to normal levels suggested a direct action of alcohol, or a metabolic product, on gonadal secretory processes, as distinct from trophic hormone effects. This study demonstrates that many of the hormonal alterations seen in cirrhosis of the liver in man may be produced directly by alcohol feeding without cirrhotic changes in the rat.
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PMID:The effect of alcohol ingestion on hepatic aromatase activity and plasma steroid hormones in the rat. 75 22

Partial hepatectomy in male adult rats results in raised serum estrogen levels and demasculinization of certain aspects of hepatic metabolism. Some constitutive forms of hepatic cytochrome P450 are sex-dependent and we have previously demonstrated demasculinization of cytochrome P450 isozyme distribution in a rat model of cirrhosis. As liver regeneration is an integral component of cirrhosis, the present study was performed to ascertain the effects of regeneration on hepatic cytochrome P450 isozyme composition and serum sex steroid concentrations. Adult male rats were subjected to 65% partial hepatectomy or sham-operation. The position-specific hydroxylation of androstenedione was used as a probe for isozyme activity. Serum sex steroids, hepatic enzymes, and hepatic deoxyribonucleic acid synthesis were measured in groups of animals at 0, 6, 24, 48, and 72 h. By 72 h total microsomal cytochrome P450 in partially hepatectomized animals had fallen to 66% of that in nonoperated animals. In both partially hepatectomized and sham-operated animals, androstenedione 7 alpha- and 16 beta-hydroxylase activity returned to preoperative levels by 48 h. However, the male-specific androstenedione 16 alpha- and 6 beta-hydroxylase activities and aromatase activity remained suppressed in partially hepatectomized liver. Serum estradiol increased eightfold in partially hepatectomized rats and peaked at 6 h followed by a gradual fall to control values. No change in serum estradiol was observed in sham-operated animals. We conclude that demasculinization of hepatic oxidative metabolism occurs in regenerating rat liver. The early rise in serum estradiol is consistent with a role for this hormone in the changes in cytochrome P450 observed, and possibly the process of liver regeneration.
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PMID:Effect of liver regeneration on hepatic cytochrome P450 isozymes and serum sex steroids in the male rat. 291 47

As of this writing, the most common cause of hepatic fibrosis is chronic hepatitis C virus infection (HCV), the characteristic feature of which is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which in turn activates hepatic stellate cells (HSCs). HSCs are also thought to be the primary target cells for inflammatory stimuli, and produce extracellular matrix components. Based on available clinical information, chronic hepatitis C appears to progress more rapidly in men than in women, and cirrhosis is predominately a disease of men and postmenopausal women. It should be noted that estradiol (E2) is a potent endogenous antioxidant. A recent study has shown that hepatic steatosis became evident in an aromatase-deficient mouse and was diminished in animals, after treatment with E2. Our studies showed that E2 suppressed hepatic fibrosis in hepatic fibrosis models, inhibited the activation of activator protein 1 and nuclear factor-kappa B in cultured hepatocytes undergoing oxidative stress, and attenuated HSC activation in primary culture. Recently, variant oestrogen receptors (ERs) were found to be expressed to a greater extent in male patients with chronic liver disease than in female subjects. We also demonstrated decreased levels of ERs in postmenopausal women and cirrhotic patients of both genders. The actions of E2 are mediated through ER alpha and beta. HSCs have also been found to possess functional ER beta but not ER alpha. A better understanding the basic mechanisms underlying the gender-associated differences observed in the development of hepatic fibrosis would provide valuable information relative to the search for effective antifibrogenic therapies.
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PMID:Impact of oestrogens on the progression of liver disease. 1264 Jul 29

Hepatitis C virus infections are recognized as a major causative factor of chronic liver disease. A characteristic feature of chronic hepatitis C, alcoholic liver disease and non-alcoholic fatty liver disease is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which, in turn, activates hepatic stellate cells (HSCs). HSCs are also thought to be the primary target cells for inflammatory and oxidative stimuli, and to produce extracellular matrix components. Based on available clinical information, chronic hepatitis C appears to progress more rapidly in men than in women, and cirrhosis is predominately a disease of men and postmenopausal women. Estradiol is a potent endogenous antioxidant. Hepatic steatosis was reported to become evident in an aromatase-deficient mouse and was diminished in animals after treatment with estradiol. Our previous studies showed that estradiol suppressed hepatic fibrosis in animal models, and attenuated HSC activation by suppressing the generation of reactive oxygen species in primary cultures. Variant estrogen receptors were found to be expressed to a greater extent in male patients with chronic liver disease than in female subjects. A better understanding of the basic mechanisms underlying the gender-associated differences observed in the progression of chronic liver disease would provide valuable information relative to the search for effective antifibrogenic therapies.
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PMID:Protection of estrogens against the progression of chronic liver disease. 1739 11

Chronic hepatitis B virus (HBV) infection is the most common cause of hepatic fibrosis and hepatocellular carcinoma (HCC), mainly as a result of chronic necroinflammatory liver disease. A characteristic feature of chronic hepatitis B infection, alcoholic liver disease and nonalcoholic fatty liver disease (NAFLD) is hepatic steatosis. Hepatic steatosis leads to an increase in lipid peroxidation in hepatocytes, which, in turn, activates hepatic stellate cells (HSCs). HSCs are the primary target cells for inflammatory and oxidative stimuli, and these cells produce extracellular matrix components. Chronic hepatitis B appears to progress more rapidly in males than in females, and NAFLD, cirrhosis and HCC are predominately diseases that tend to occur in men and postmenopausal women. Premenopausal women have lower hepatic iron stores and a decreased production of proinflammatory cytokines. Hepatic steatosis has been observed in aromatase-deficient mice, and has been shown to decrease in animals after estradiol treatment. Estradiol is a potent endogenous antioxidant which suppresses hepatic fibrosis in animal models, and attenuates induction of redox sensitive transcription factors, hepatocyte apoptosis and HSC activation by inhibiting a generation of reactive oxygen species in primary cultures. Variant estrogen receptors are expressed to a greater extent in male patients with chronic liver disease than in females. These lines of evidence suggest that the greater progression of hepatic fibrosis and HCC in men and postmenopausal women may be due, at least in part, to lower production of estradiol and a reduced response to the action of estradiol. A better understanding of the basic mechanisms underlying the sex-associated differences in hepatic fibrogenesis and carciogenesis may open up new avenues for the prevention and treatment of chronic liver disease.
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PMID:Female hepatology: favorable role of estrogen in chronic liver disease with hepatitis B virus infection. 1770

Estrogens play important roles in the cell proliferation and invasion of estrogen-dependent human neoplasms. Aromatase overexpression has been also reported in hepatitis and hepatocellular carcinoma (HCC) compared with normal liver but its details in these hepatic disorders have remained unclear. Therefore, in this study, we first immunolocalized aromatase using immunohistochemistry in patients with liver cirrhosis, steatosis, hepatitis, HCC, and metastasis liver carcinoma (MLC) in order to study the detailed status of intrahepatic aromatase. Aromatase immunoreactivity was predominantly detected in nonneoplastic hepatocytes around tumor cells. We then evaluated the effects of an interaction between hepatocytes and carcinoma cells upon aromatase mRNA expression, using HepG2 as a substitute model of hepatocytes by coculture systems. Aromatase mRNA levels in HepG2 were significantly increased by coculture with all carcinoma cell lines examined. We also evaluated alternative splicing of aromatase exon 1 but the same splicing variant was used in HepG2 cells regardless of carcinoma cell lines employed in the coculture system. These findings obtained in HepG2 indicated that carcinoma cells, whether metastatic or primary, induced aromatase expression in adjacent normal hepatocytes possibly through the soluble aromatase inducible factors in human hepatic microenvironments.
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PMID:Aromatase in human liver and its diseases. 2393 Feb 7